    #include "stdio.h"
    #include "stdlib.h"
    #include "string.h"

    #include "net/if.h"
    #include "arpa/inet.h"
    #include "linux/sockios.h"

    int main(int argc,char *argv[])
    {
        struct sockaddr_in *addr;
        struct ifreq ifr;
        char*address;
        int sockfd;

        char *name = "eth0";
        if( strlen(name) >= IFNAMSIZ)
            printf("device name is error.\n"), exit(0);

        strcpy( ifr.ifr_name, name);

        sockfd = socket(AF_INET,SOCK_DGRAM,0);

        //get inet addr
        if( ioctl( sockfd, SIOCGIFADDR, &ifr) == -1)
            printf("ioctl error.\n"), exit(0);

        addr = (struct sockaddr_in *)&(ifr.ifr_addr);
        address = inet_ntoa(addr->sin_addr);

        printf("inet addr: %s\n",address);

        //get Mask
        if( ioctl( sockfd, SIOCGIFNETMASK, &ifr) == -1)
            printf("ioctl error.\n"), exit(0);

        addr = (struct sockaddr_in *)&ifr.ifr_addr;
        address = inet_ntoa(addr->sin_addr);

        printf("Mask: %s\n",address);

        //get HWaddr
        u_int8_t hd[6];
        if(ioctl(sockfd, SIOCGIFHWADDR, &ifr) == -1)
            printf("hwaddr error.\n"), exit(0);

        memcpy( hd, ifr.ifr_hwaddr.sa_data, sizeof(hd));
        printf("HWaddr: %02X:%02X:%02X:%02X:%02X:%02X\n", hd[0], hd[1], hd[2], hd[3], hd[4], hd[5]);

        exit(0);
    }
